The invention relates to windows in general, and more particularly to improvements in casement windows. Still more particularly, the invention relates to improvements in casement windows wherein the sash can be releasably arrested or locked in closed position.
It is already known to provide the frame and the sash of a casement window with cooperating stationary and mobile detents and with an actuator which can move the mobile detents into engagement with the adjacent stationary detents in closed position of the sash. This ensures that the sash remains in closed position until and unless the arresting or locking device is deactivated by moving the actuator and the mobile detents to inoperative positions. As a rule, or at least in many instances, the sash is pivotably mounted in the window frame (e.g., on pairs of links) in such a way that it moves outwardly (beyond the outer side of the frame) during pivoting to its open position. The drive which must be manipulated to pivot the sash is provided with a self-locking transmission which ensures that the sash remains in a selected position except when an operator decides to manipulate the drive in a sense to move the sash to the closed position, to the fully open position, or to any one of a number of intermediate positions. Thus, the angular position of the sash cannot be changed by exerting a pulling or pushing force directly against the sash; this ensures that gusts of wind cannot change the selected position of the sash. The locking device not only secures the sash in the closed position but also ensures that the border of the sash is in proper engagement with the adjacent portions of the frame so that the customary weatherstripping between the frame and the sash is fully effective as soon as the sash moves to and as long as the sash remains in closed position. Proper engagement of the sash with the frame is particularly desirable and important along the two vertical jambs of the frame.
The actuator for the mobile detents of the locking or arresting device is normally recessed into a groove in the border of the sash. In heretofore known windows, the actuator is moved between operative and inoperative positions by a handle which is provided on the sash, i.e., by a handle which does not form part of the aforementioned drive serving to pivot the sash between its open and closed positions. Thus, the operator in charge must manipulate the handle to move the actuator and the mobile detents to inoperative positions prior to manipulation of the drive which is to pivot the sash from the closed position. Inversely, the drive must be manipulated first in order to return the sash to the closed position, and the handle is manipulated thereafter to return the actuator and the mobile detents to their operative positions.
Published European patent application No. 0 323 241 discloses a casement window wherein the sash is caused to pivot outwardly beyond the outer side of the frame during movement from closed to open position. This publication further discloses a crank drive which can be used to pivot the sash as well as to move an actuator of the locking or arresting device between operative and inoperative positions. The crank drive is directly coupled to the actuator which forms part of the locking device and is recessed into a groove which is provided in the frame. The actuator extends along that portion of the sash which is remote from the hinge for the sash. Thus, the locking device which is disclosed in this publication is designed to lock the sash to the frame only along one jamb of the frame so that the establishment of a reliable sealing action between the frame and the sash (in the closed position of the sash) is highly unlikely The actuator cannot be caused to surround a major part of the sash because it is installed in the frame. Such mounting prevents the actuator from extending along one or more corners of the frame because this would interfere with movements of the sash to the closed position.